The present disclosure relates generally to electronic displays and, more particularly, to devices and methods for achieving more precise gray level control and an increased aperture ratio in active matrix organic light emitting diode (AMOLED) electronic displays.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Flat panel displays, such as AMOLED displays, are commonly used in a wide variety of electronic devices, including such consumer electronics as televisions, computers, and handheld devices (e.g., cellular telephones, audio and video players, gaming systems, and so forth). Such display panels typically provide a flat display in a relatively thin package that is suitable for use in a variety of electronic goods. In addition, such devices may use less power than comparable display technologies, making them suitable for use in battery-powered devices or in other contexts where it is desirable to minimize power usage.
AMOLED displays typically include picture elements (e.g. pixels) arranged in a matrix to display an image that may be viewed by a user. Individual pixels of an AMOLED display may generate light as a voltage is applied to each pixel. The voltage applied to a pixel of an AMOLED display may be regulated by two thin film transistors (TFTs). For example, a circuit switching TFT may be used to regulate current flowing into a storage capacitor, and a driving TFT may be used to regulate the voltage being provided to the OLED of an individual pixel. Connections between the TFTs in an AMOLED display may extend through an area of the pixel that may otherwise be used for displaying image data. In certain configurations, a pixel aperture ratio is a ratio between a transparent area of the pixel that can be used to display image data and a total area of the pixel. Thus, connections between the TFTs may decrease the area of a pixel that can be used to display image data and thereby lower the aperture ratio of pixels of the AMOLED display.
In electronic displays, the gray level of each pixel may determine the intensity of the output of the pixel. In certain displays, the intensity of each pixel's output may vary from black at the lowest intensity to white at the highest intensity. As mentioned above, one of the TFTs of an AMOLED display may regulate a voltage being provided to the OLED of an individual pixel. The range of voltages that is applied to a gate electrode of the driving TFT may determine the amount of current flowing to the OLED and thus, the gray scale level of a pixel. An increased range of voltages that may be applied to the gate of the driving TFT may give more precise control over the gray level in an AMOLED display.